THIS invention relates to a preservative and fire retardant composition and combination and process.
Cellulosic materials, typically wood and wood derivatives, such as cardboard and products comprising them, need to be protected against the risk of fire and against biological degradation as a result of decay caused by fungi and attack by insects such as wood borers and termites. Borates in low concentrations have been used as wood preservatives as they provide wide-spectrum protection against organisms causing wood degradation. Borates in high concentrations have also been used to treat wood against fire. However, the use of high concentrations of borates is expensive and uneconomical. Also, borates have a relatively low solubility in aqueous solvents and it is therefore difficult to formulate a suitable composition for impregnation. Borates are also leachable from wood and other cellulosic materials which can result in their loss from treated cellulosic materials when they are exposed to continuous wet conditions, in particular free water.
Other cellulosic materials such as thatching grass, reeds, bamboo and palm leaves are also used in root and wall construction. These also need to be protected against the risk of fire and against biological degradation. However, to date the treatment of such materials has posed problems because the waxy and/or protective coating on the surface of such materials precludes sufficient penetration of treatment materials.